


What Have I Done

by devil_enchantment



Category: Chicago Fire, Chicago PD (TV)
Genre: F/M
Language: English
Status: In-Progress
Published: 2017-12-31
Updated: 2017-12-31
Packaged: 2019-02-24 14:16:49
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 4,761
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13215522
Author URL: https://archiveofourown.org/users/devil_enchantment/pseuds/devil_enchantment
Summary: ...Enrique Pena Nieto once said that "behind every crime is a story of sadness." What if Antonio and Gabriela Dawson had another sibling who hasn't been around in years after leaving the city of Chicago and those who loved her behind then suddenly turned up again? How would they react and why did their sister come back after all these years of not being around?





	What Have I Done

**Author's Note:**

  * For [Nicole](https://archiveofourown.org/users/Nicole/gifts).



> First I want to say thank you for helping me, Nicole with not only proof-reading it but also adding snippets here and there within the first chapter. You are a great friend and a true sister. To those ladies who I think are absolutely amazing and wonderful and the best sisters you could ever ask for, thank you for all your support too as it means a lot and I don't think I'd be able to write any OneChicago related fics without any of you. xxx
> 
> And for this story in particular, I was thinking about the idea of Antonio and Gabriela having a sibling who after so many years of not being seen or heard from directly has suddenly turned up in the city of Chicago, on the exact date she left all the years earlier and then I wanted to know why we wouldn't know her, why she would come back, how they would react etc. 
> 
> So here goes nothing.

* * *

_“First rule of a gunfight: bring a gun. Second rule: bring friends with guns. Here’s to having friends in Chicago.” – Antonio Dawson, Chicago P.D._

* * *

 

 **Friday, 24** **th** **November 2017. – Chicago, Illinois. – Evening.**

* * *

Nineteen years ago, on this very day was when his sister, Dianna who was the first daughter born to his parents; Camila and Ramón – left the city as she was on a different path to what him and their youngest sister, Gabriela were on.

 

His sister was a criminal who got away; in the eyes of several police officers he knew as she worked her way up in the ranks like she would have done if she only went into the profession that Antonio found himself in; but nothing stuck long enough to get her put in prison, as witnesses would retract their statements or not even the forensic specialists could prove she was there.

 

Antonio could say that her departure from the city, even from the United States was the catalyst that opened the wide jaws of the raw, gaping wound that was his relationship with his father, Ramon – but then that would mean he wasn’t at fault in the slightest.

 

His mind seemed to snap him back into reality; after there was a tap on the window and there was Halstead, looking annoyed, as the two had been called out to a crime scene, just as they got to Molly’s with them using Halstead’s GMC Sierra pick-up truck. Not knowing why, he thought about his sister who had been gone for years and his thoughts about her soon disappeared as he had to move quick as Voight, Olinsky, Burgess and Upton were already on scene.

 

A young man, no older than sixteen or seventeen was laying on his back, his eyes stared without seeing, the ghost of fear still etched upon his face as the unidentified young male must have been terrified before he drew his last breath.

 

Upton was the one who pulled the white sheet back over the body, as Antonio, Voight and Olinsky discussed something as this new case had a familiar tone to it; as the way the body was placed and the fearful expression on the victim’s face was like what happened to three victims over ten years ago.

 

The case was never fully-solved, as the evidence never seemed to share a link with what they found afterwards and there was no connection between any of the victims; so, the thought of it matching another unsolved case and the killer never being brought to justice disturbed Upton and Kim the most.

 

“Antonio.”

 

Ruzek managed to get his attention; after Antonio, Voight and Olinsky stopped talking as Voight wanted to speak to Upton, Jay, Atwater and Burgess as the four were given the task of making those who were sticking around to see what was going on leave and start collecting witness statements from anyone who wanted to talk.

 

“What?”

 

“Is that your newest fling or something?” asked Ruzek, abruptly as it caught Antonio off guard and he was confused, as well as annoyed with what Adam asked him because they were at a crime scene, a teenager who was at least his daughter Eva’s age was dead and now his _friend_ was asking him about a fling.

 

It was only because Adam gestured towards a woman who was stood on the sidewalk, that Antonio saw her staring at the three detectives who were stood close together with Olinsky having just hit Adam on the back of the head for his inappropriately-timed question.

 

Ruzek grunted and wanted to know why Alvin hit him on the back of his head when it was like time stopped; as Antonio stared at the caramel-brown haired woman who had a bold, jagged scar that went from the left side of her forehead, cutting across her face to the right side of her jaw.

 

“Antonio?” said Olinsky, as he put his hand on his friend’s shoulder and was prepared to shake him if he didn’t respond as even Adam stopped fooling around; sensing that something was wrong with the broad-shouldered, black-haired detective as he kept staring at the woman.

 

She was a dark shadow, empty and hollow, like death.

 

**“Dianna.”**

“No, that’s Al…” said Adam who was only joking when he got glared at by Alvin immediately after the words left his mouth and the grin that was on his face slipped away; as Antonio shook Al’s hand off his shoulder before he took off towards the woman.

 

Atwater was the one who joined Adam first as Alvin didn’t even say a word as he went after Antonio, as though he was going to stop him and Ruzek was stood still; staring not at his best-friend but towards Alvin and Antonio; as the former grasped the latter’s arm in a tight grip.

 

“Who is Dianna?”

 

That was the question which Ruzek wanted to know the answer too and there was this anger in Antonio’s face which made Adam want to go over there, to tell Alvin to let him go and see the woman who had been staring at the Detectives, especially Antonio since they arrived.

 

“What’s going on?” asked Jay, who had come over after not only collecting some witness statements but having helped Kim with two men who started getting aggressive when they weren’t allowed to have a closer look at the body.

 

“Get off me, Al.” Antonio snapped, as he wasn’t in the mood to be stopped as the woman didn’t move a muscle, her eyes only narrowed when she saw him coming towards her and it wasn’t something Olinsky wanted to do; as he knew the name as Dianna Sinclair was a Dawson once.

 

“You can’t speak to her, not here.” Alvin knew he wouldn’t want to listen, but the uniformed officer who was trying to get the crowds to disperse noticed the commotion and would have more than likely put his own spin on things. He could even think the woman was a suspect, even if she didn’t start running off.

 

His jaw clenched, as he was ready to even push Alvin away hard enough for him to stumble at least but then out of the corner of his eye;  he saw the others standing close together except for Voight and Upton - the concern on Kim’s face at her partner’s behaviour, the confusion on Ruzek’s and _what the hell is going on_ expression on Atwater and Jay’s face.

 

His eyes narrowed as he turned back to where his sister was, the same blank expression on her face as there was when he last saw her and her eyes flickered with an emotion; he couldn’t describe. There was no smile, no taunting smirk on her face, as her lips were pierced together in a thin line and then her eyes weren’t on him or Alvin anymore; as she stared at the officer who was moving closer to her and those who were still on the sidewalk.

 

Antonio knew it could go one way or the other; as his sister never used to always be polite towards police officers when they approached her, especially if she thought they were being rude and the fact that she always watched people like a predator stalking its prey, was unsettling towards those who did approach her. His jaw clenched as he watched the officer get closer to Dianna and before words could escape the officer’s lips; there must have been something said by either her or someone close to her as all his sister did was give him one last glance before turning around and walking off.

 

Antonio couldn’t stop her from walking away, he couldn’t grab her arm and welcome her home; not only because Alvin still had a tight grip on his arm but because he knew she wouldn’t let him, not even if he was her younger brother.

 

“Come on, we got work to do.” Alvin told him, letting go of his arm once he watched Dianna walk around a corner and disappeared before Antonio shook his head, scowling as he walked back towards where Halstead parked earlier.

 

The tension that rolled off him was noticeable as soon as Jay got in the pickup with him being wary, as he was about to ask Antonio if he wanted to drive then suddenly decided it was better not to ask him anything until they were on their way back to the district.

 

“Who is she?”

 

“She’s my sister.”

 

Jay glanced at him, more in shock than anything as he knew it wasn’t Gabriela which meant the entire time he knew Antonio and even Gabby; there had been a large family secret as neither Antonio or Gabriela ever mentioned another sibling; let alone a sister. 

 

“But why don’t…”

 

“I haven’t seen her in nineteen years, Jay.”

 

Halstead couldn’t imagine not seeing his brother Will for that long. He would want to go after him, bring him back and try figure out what went wrong in the first place - no matter what happened between them or even between his brother and his family but it wasn’t him who hadn’t seen his sibling for 19 years.

 

It was Antonio.

 

The rest of the drive to the 21st District was quiet; as Antonio didn’t seem in a talkative mood and Jay didn’t know what to say, let alone ask him. He thought he knew him, but then he told himself that everyone had secrets, including those in Intelligence.

 

Antonio stared out of the window, his thoughts plaguing him this time around instead of the nightmares that he experienced on and off since he found out from his mother, Camila that the last contact she had with Dianna was when her husband William sent a letter addressed to Camila and Ramon.

 

He was so angry by it at the time - he was angry at the person who he held responsible for making his sister leave the city of Chicago in the first place as Antonio never agreed with her marrying someone like William.

 

_“You can’t do this. You can’t leave, not now…” Antonio, had never heard such despair in his mother’s tone before and he didn’t mean to eavesdrop on the conversation his Ma was having with someone._

_It was like a one-sided discussion at first, as he didn’t hear anyone speak but he did hear someone sigh and he wondered if his father was in the room too or if it was just his mother and the person she was arguing with. He hoped in the back of his mind; that it was one of his Aunt’s - rather than the person he knew wanted to leave eventually, his older sister Dianna had a strong personality and he liked to think she was far more stubborn than him._

_“Antonio could…”_

_“What could he do, Ma? What could **Officer** Antonio Dawson possibly do for me? Tell…” _

_“Don’t speak to your mother, like that.”_

_“Why not? It is after all the way you speak to her sometimes.”_

That horrible sinking feeling was back again as he realised that Dianna who wasn’t there when Ramon told everyone that he and Camila were getting divorced - already knew their parents were going through a rough time. 

Antonio never understood at first as to why his sister left; he knew she was in some kind of trouble and that she was being watched by the Gang Unit but he at the age of nineteen hoped she would see sense and get off the destructive path she was heading down as she had warned him, argued with him that the path he had been on was a dangerous one which was why he chose to get off it - to go and work towards being a Detective in the Chicago Police Department.

 

He wasn’t there for her in the weeks before she left and Dianna was always the one who told him to go into another profession - something less dangerous and he always thought it was because she never wanted him to see the other side of her, her breaking the law and him not being able to do anything for her.

 

_She’s still family. No matter what._

It was all a blur to him when they arrived at the District, as he got out of the vehicle and went in through the main door without saying anything to anyone. Platt looked concerned as Jay shook his head when she must have been about to say something and all they did was go up the steps, letting themselves into the Unit.

 

Burgess was already there, at the whiteboard with Upton and putting the photographs up of the crime scene with there not being that many details on the board. Atwater and Ruzek were discussing something with them only merely glancing at Antonio and Jay as Olinsky was in Voight’s office.

 

“What’s going on?” asked Halstead as he went to sit down at his desk, like it was just another night and another case.

 

“Voight was _arguing_ with the Commander before,” Ruzek muttered with Kim grimacing as clearly Antonio and Jay had been not only the last ones to arrive but they had managed to avoid seeing Commander Crowley.

 

“Why?”

 

Ruzek shrugged.

 

In the back of Jay’s mind; he wondered if it was to do with what happened at the crime scene, as Alvin was the one who stopped Antonio from getting to his sister but then if the rest of the team didn’t know he had another sibling - what’s to say the Commander did. The door to Voight’s office opened, Olinsky being the only one to step out as Voight remained in his office and Jay watched Al from the corner of his eye as he approached Antonio, whispering something into his ear.

 

Antonio knew it would have been talked about at some point, but not so soon. He knew there could be another reason why his sister was there, why she was watching them work as she could have been there when the man died. But that was speculating, and as her brother - he knew he couldn’t throw her to the _wolves,_ he had to protect her because that was his responsibility yet in his line of work; he had to think that she could be a suspect too.

 

_If only he didn’t see her._

So when he entered Voight’s office, he didn’t look at him as he shut the door and then when he did, he refused to sit down as he preferred to stand up this time. It reminded him of the time when he thought Voight was trying to push him out of Intelligence when ASA Stone told him that Hank had signed off on the job offer; yet he knew this was different.

 

This was about family.

 

“You going to tell me I shouldn’t have tried to go speak to her? That I should have said something to you first,” his anger was getting the better of him as he spoke, not letting Voight say anything because even after the years having passed by; he still had to try and protect her.

 

“It’s not…”

 

“Don’t.”

 

“Five weeks ago, a crew came into the city,” said Voight who explained what the _argument_ between him and Commander Crowley consisted of, as there had been three crew members missing when they entered the city and the crew stayed for at least five days in total before disappearing.

 

Antonio didn’t want to hear it, he didn’t want to think his sister was getting involved in something that he would have used to consider as being out of her league but Dianna had always been a firecracker, and on the other side of the law.

 

“Antonio...”

 

He shook his head, not wanting to hear anymore as investigating the crew wasn’t their case, their priority was solving the murder of a teenage boy and bringing the killer to justice with him not thinking straight as he didn’t want to think his sister had a part in the boy’s death.

 

“What matters right now is the case.”

 

Antonio wanted to block it all out and get back to work with Voight being about to say something when suddenly, Ruzek came in and told them that Upton had some information that they needed to hear with it being about the case as soon as Antonio left the office, back into the bullpen.

 

* * *

 

 

It was a fairly steady night especially for a Friday and Gaby had just finished serving someone a drink when her phone rang, not once or twice but several times until she managed to get it out of her pocket as she let Otis take over once she saw whose name flashed up on the screen.

 

“Hey, Antonio…” Gaby managed to get past Herrmann as she answered the call with her having been confused at first as she remembered the text that her brother sent to her as him and Halstead were called away to a scene.

 

“Hey, sis…”

 

It was the way he greeted her that she knew something was wrong and soon got herself outside, away from the noise as there were several people who had come into the bar at once as it was getting busier as the time passed.

 

“Has something happened?”

 

“You’re not going to believe me.”

 

“Antonio, you’re scaring me.”  Gaby feared the worst when Antonio talked like this.

 

Antonio took a moment.  “Gaby… Dianna… she’s back.”

 

“What?!”  Gaby didn’t believe him.  “Not possible.  She abandoned us all those years ago.”

 

“I saw her… she’s changed… but Gaby… it was her.”

 

“Where are you?”

 

“The district.”

 

“I’m coming to you.”  Gaby said.

 

“No.”  Antonio didn’t want to add to her stress by explaining why and where he’d seen their sister.

 

“Antonio, either you tell me what the hell is going on around here… or I’m coming and finding out for myself.”

 

“Meet me outside.  I’ll fill you in there… can’t… the walls have ears.”

 

“Okay.”  Gaby agreed and ended the call.

 

Antonio put his cell away and looked around.  He had to make sure no one knew what he was about to do.  While his sister had walked out on their family, she was his sister.  He had to do everything to protect her.  He just couldn’t bring himself to believe that his sister, the woman he thought of as his hero growing up, could be involved in this mess.

 

He could only hope that her husband wasn’t part of this mess because if he was; then it wouldn’t end well.  Antonio had never liked William and his dislike for him turned into hatred when he saw him hit her once and then after what happened next; his sister never spoke about it again.

 

Pacing around; he was close to the main door to the District but not too close as he told Halstead - he was going to go get something to keep him going and get fresh air. He knew he would have to pick up some of the food that Ruzek, Atwater and the others requested him to get but he’d get that task done as soon as Gabby met up with him.

 

All sorts of emotions were going through him and he took a deep breath when he saw Gabriela walking towards him as he’d seen her get out of a cab.

 

“Where…” Antonio gave her a look that made her stop talking as he wanted to walk away from the District, to talk about it on their way to a store so he could get what he told the others he would.

 

“Ruzek was the one who saw her first.”

 

“But you and Jay were coming to Molly’s…” Gaby was confused as it didn’t click as to where their sister had been and her emotions were chaotic.

 

“She wasn’t near the bar, was she?” said Gaby, realising what he meant after Antonio didn’t say anything, but then he didn’t have to.

 

His face said it all.

 

“I didn’t get to speak to her.”

 

“Why would you want to speak to her after…”

 

“Mom was heartbroken when Dianna left and what Dad said wasn’t what…”

 

Gabriela stopped walking and suddenly had her hand on his arm, pulling him out of the way of someone walking the opposite way to them. “You weren’t there.”

 

“I was there when he told her if she walked out of that door, not to come back…” He was frustrated as he didn’t know everything as to what happened the day, Dianna left for good but his relationship with his father deteriorated after witnessing the argument between Dianna and Ramon.

 

Gaby was all for seeing her sister again, she looked up to her in a way that made no sense in the end; considering what Dianna got herself into but knowing she was different in a way that must have shocked her brother disturbed her.  “So, why come back now?”

 

He shouldn’t be telling her anything, because it could well and truly be related to the case, but he couldn’t just stand there and lie to Gaby’s face. “They think she’s part of a crew who arrived in the city, a few weeks back.”

 

Gabriela gave him a confused look. “They?” She hesitated, then repeated a question she had asked him to do with women not being able to keep their hands off him; now that he was on the dating scene again but that was all in jest, this was serious. “Who is they?”

 

“Voight.”

 

“But it’s not just Voight who thinks that, is it?”

 

“Gaby…”

 

She shook her head and started to walk off in the direction they were heading in with Antonio grimacing; as he went after her. It wasn’t easy for him to face the fact that his sister could have come all the way back to Chicago from wherever she was in the world to complete something that was either started recently or a long time ago.

 

“Do they know about her?” asked Gaby, after they managed to cross the road and get to where they needed to be as they had spent a few minutes just walking instead of talking as they both needed to come to terms with the return of their sister.

 

“Yes.”

 

They promised each other, a long time ago that they wouldn’t speak about Dianna. Not to anyone who didn’t know them properly; as talking about their sister was hard and got even harder as the years passed by. Only Matt and Peter had seen the photographs that Gaby kept in a photo album that her mother had given her as a birthday present once with her not going into too much detail about Dianna and what happened to her.

 

Now, she knew it would be time to tell her family at 51 about her sister. Just in case anything happened, like Dianna showing up there without any warning. It was inevitable as she couldn’t have stayed away forever. Unless of course, she died and then they would be burying her.

 

Would that have been better? If she had to tell her family, the ones she worked with everyday since she came to 51 and saw some people come and go - that her sister was dead instead of alive.

 

“Mom needs to know.” Gaby declared, abruptly as she let Antonio grab the door for her that time and they entered the store with her not needing to grab a basket unlike her brother as he had an order to get for the rest of Intelligence.

 

“I’ll try and go see her tomorrow.”

 

He would also tell Ramon if he had to, but he didn’t exactly want to speak to his father especially not about Dianna as the last time her name was brought up was in the aftermath of the disastrous 40th wedding anniversary for his parents. He didn’t want to put pressure on his mother either as she was stressed enough, though she kept deleting the messages that Ramon sent her, merely deleting them as soon as she received them and the whole family had been in shock when the divorce was announced - they were still in shock even as the time passed as no one expected it.

 

Especially Gaby.

 

“You should speak to Laura,” Gaby murmured, after a short while with him having selected several different drinks that he knew everyone liked and then almost dropped the bottle of water that he picked up for himself.

 

“Why should I do that?”

 

Laura and Antonio weren’t on good terms, he wasn’t happy that she was indirectly responsible for him and Sylvie breaking up even though they were moving too fast and now Eva was living with him as her, Laura and Laura’s newest boyfriend weren’t getting along.

 

“She knows about her, Antonio. Eva and Diego have…”

 

“They’ve only ever seen photos of her, that were taken years ago. And she’s a lot different now than she was back then,” he struggled to get the words out of his mouth, he didn’t want to stress her more especially when they could only speculate as to why she had so many scars on her skin.

 

Knowing his sister’s photograph was on the whiteboard with her name on it as she was potentially going to get talked to by someone in the team that wasn’t him unless he could ignore the fact that he was related to her and focus on the case - made it harder for him to talk to Gaby about it.

 

“They need to know.”

 

His phone rang before he could say anything and he got it out of his pocket as Gaby helped him out by grabbing the basket that he had grabbed to put the snacks and drinks in with him noticing it was Alvin calling him which made him answer it quicker.

 

Gaby was nervous.

 

She didn’t know what to think about the whole situation, knowing her sister was at the crime scene, watching what was going on was enough to know something else must have been going on as Dianna hadn’t entered the city, not even once since she abandoned them.

 

“...I’ll be there soon.”

 

The call ended, and he walked back over to where she was which was by the cash register as he moved away while he was talking to Alvin, so no one knew that he met up with her at such a late hour as she was supposed to be working with Gaby taking a deep breath, seeing the look in his eyes.

 

“Go,” said Gaby, as she handed him a bag of the snacks and drinks he had gotten since she not only paid for her own but his too with him not letting her say no to him paying her back as they left the store with him having to get back to the District and she had to get back to Molly’s.

 

 

* * *

**Saturday, 25th November 2017 - Chicago, Illinois. - Early Morning.**

* * *

 

_Breathe In._

 

It was later than Antonio would have liked to have got home and was grateful in a way that Eva was staying at a friend’s for the night with him having made sure to have stopped off at Molly’s before going home as he wanted to check on Gaby and to see if Dianna had showed her face in the bar. He was told by Casey that there had been no sign of her with it making him anxious; as he wanted to know where his sister was.

 

It took less than three minutes to realise something wasn’t right as he had a bad feeling deep in the pit of his stomach when he reached his front door and he couldn’t get himself to think straight as he grabbed his gun out of his holster before his hand touched the handle with him pressing the handle down.

 

The door was unlocked.  Raising his gun, he pushed the door open and quietly shut it behind him once he got inside his apartment. If Eva was home for some reason by herself; he’d immediately put his gun down and ask her why she was still up. If it wasn’t Eva, then he’d keep his gun up and ready to fire.

There, sitting at the table in the kitchen was the last person he ever expected to see in his apartment. A gun was laid on the table, and a knife was being twirled in between her fingers. Her lips twisted a little and he saw a sly smirk on her face as his gun was still aimed at her.

 

“Dianna.”

 

“Hello, brother .”

 

_Breathe Out._

 

 

 

 

 


End file.
